If you are in development and using a database sandbox auto created and managed for you with DBIx::Class::Migration, this is a trait to make it easy to hook that sandbox up to your Catalyst application. The following are roughly the same:

The biggest reasons to use this trait would be it makes it harder to connect the wrong database and it gives you some easy helpers for automatic database installation and fixture population (as you can see in the above example).

A hashref of init arguments that you'd pass to the new method of DBIx::Class::Migration. schema_class is inferred from the existing config parameter, so you don't need to pass that one. Other arguments of use could be db_sandbox_class.